The present invention is directed to a vertical packaging machine for forming, filling, and sealing bags from a flexible elongated web which is wound on a reel wherein the bags have an erectable self-supporting tensile structure with a quadrangular flat bottom without side bellows, an upper sealing flap and triangular ears associated with the bottom and which are affixed to the side walls of the bag or against the flat bottom of the bag. The wedge-shaped structure of the bags, which are sequentially produced by the vertical packaging machine, provide an intrinsic stiffness which offers a maximum exhibit surface for advertising which will be maintained in the upright position.
Automatic vertical packaging machines are known which utilize a flat elongated web wound on a reel to form airtight, filled, sealed containers. The flat elongated web is wrapped about a hollow mandrel and is longitudinally sealed by means of a thin strip of heat sealing material covering the overlapping edges of the web to give the web a tubular configuration. Other prior art machines utilize an extruded tubular web which is free from longitudinal machines. Other known packaging machines have means for evacuating air from formed and filled bags before sealing the bag opening so as to achieve a certain degree of vacuum which remains even after the bag is sealed. Still other prior art packaging machines are provided for filling bags with sterilized substances such as long-life milk. The operation of these machines is carried out under conditions of absolute asepsis wherein the inner surface of the bag is sterilized and the filling and sealing operation takes place without any contact with the environmental atmosphere, thus producing an absolutely aseptic package, thereby guaranteeing the long life of the product.
Prior art packaging machines are known wherein the extruded tubular web or the seamed tubular web formed from a flat flexible web form, fill, and seal pillow-shaped bags with or without side bellows. Such bags have the disadvantage that they cannot stand for the exhibition of advertising for every single bag. At present, the trend is toward erectable packages having a self-supporting structure. Many flexible bags are provided with small additional bases so as to enable the bag to stand. Filling machines are also known to introduce sterilized milk or various other drinks into semi-flexible cartons. The cartons used in these machines are pre-shaped and fed horizontally from a magazine wherein the cartons are stacked in folded condition. In such prior art machines the carton is withdrawn and opened and then sterilized and filled with sterile liquids before being sealed under aseptic conditions.
Machines for carrying out the packaging of sterile liquids under aseptic conditions are also known wherein the packages are formed in a vertical array. Machines of this type give the container the form of a pillow with four protruding side ears. Afterwards, the filled pillows with the four side ears still protruding therefrom are conveyed to separate units which turn over the four side ears and fix them to the side walls or top of the bag, thus giving the bags the form of cushion-parallelopiped containers. Such machines involve a very complex sequence of operations.